Architecture differentially affects thermal properties of Song Thrush Turdus philomelos nest walls

Abstract

ABSTRACT Thermistors embedded on and within the nest wall were used to measure the changes in temperature between different parts of the architecture of the wall of Song Thrush nests as heat from a light bulb was conducted across the wall. The wood pulp forming the nest cup provided the greatest resistance to heat loss across the nest wall. Despite differences in nest mass and architecture, thermal conductance for Song Thrush nest walls were not statistically different from values previously reported for Common Blackbird Turdus merula nests. Song Thrush nests constructed over many years in the same geographical location exhibited an increase in the thickness of the wood pulp cup and a reduction in thermal conductance, i.e. the most recent nests were better insulated. However, nest mass or thermal insulation did not affect reproductive success between years.